This department was so titled from 1880-1888. However, the Commissariat & Transport DEPARTMENT existed from 1875-1880. Buttons to both are not scarce but those with extremely good gilt are worth having. Generally speaking, only 25mm buttons are of value, smaller ones are generally spurned by collectors. So, a 25mm button would change hands for 5-8 pounds in good condition, 8-12 pounds in very good condition and those retaining all their gilt 12-20 pounds. Wilkinson-Latham's book is such a hotch-potch of this and that, I am afraid it doesn't really qualify as a reference work - far too many errors. Howard Ripley's book, however, is a must for button collectors - preferably the 2002 edition known as Ripley 2. If you end up with any spare buttons from your acquisition, I would welcome the opportunity to purchase two or three. Regards. David